Electric circuit interrupter



Dec. 23,` 1941. s. FARRER :a1-AL 2,267,399

ELECTRIC CIRCUIT INTERRUPTER v Filed May 17, 1940' Pagg.

Inventor-s Sydney Farr-er; George Pailn,

heur' Attorney.

Patented Dec. 2.3, 1941 ELECTRIC CIRCUIT INTERIHJPTERl Sydney Farrer,Lynwood Grove, Sale, and George Pailin, Higher Openshaw, Manchester,England, assignors to General Electric Company, a corporation of NewYork Application May 17, 1940, Serial No. 335,858 In Great Britain June1, 1939 6 Claims.

Our invention relates to electric circuit interrupters of thefluid-blast type in which interruption of the circuit is effected by ablast of arc-- extinguishing fluid through the arc drawn during circuitinterruption and more particularly is an improvement on United StatesLetters Patent 2,146,656 granted February 7, 1939, upon an vapplicationof'W. F. Skeats and assigned to the same assignee as the presentinvention.

It is an object of our invention to provide a new and improved aircircuit breaker of the gas-blast type havinga large interruptingcapacity which is simple and compact and which is effective to interruptcurrents of greatly varying magnitudes. Another object of our inventionis the provision of a simple and compact circuit-breaker constructionembodying means for drawing a plurality of arcs in series, one of whichcauses the generation of the gas under pressure during circuitinterruption, which is driven across the other arc to extinguish thesame and interrupt the circuit.

. While not limited thereto, our invention is particularly applicable togas-blast breakers of the type wherein an arc-extinguishing gas isemitted which is mounted a fixed electrode I2 projecting axially intothe chamber defined by cylinder I0.

Fixed electrode I2 is illustrated as being capable of limited movementagainst the bias of a spring I3 so as to provide the necessary wipe whencooperating with a movable electrode, to be described hereinafter,during the circuit-closing and opening operation. The cap II is alsoprovided with a suitable terminal, not shown, for connecting the cap tothe external electrical circuit I4. l

A rod Contact I5 is mounted axially within cylinder I and arranged forreciprocation 'withm in the latter by any suitable operating mechanism,not shown, which may be disposed outside said cylinder to open and closethe circuit as desired. One end of said rod contact I is provided with asuitable electrode or butt Contact from the walls of an arc-confiningchamber under the influence of the arc and it is, accordingly, an objectof this invention to provide a new and improved circuit breaker of thistype.

Further objects and advantages of our invention .will become apparent asthe following deseription proceeds and the features; of novelty whichcharacterize our invention will be pointed out with particularity in theclaims annexed to and forming a part of this speciiication.

For a better understanding of our invention, reference may be had to theaccompanying drawing in which Fig. 1 is a cross-sectional View of acircuit breaker embodying our invention, Fig. 2 illustrates anothermodication of our invention,

Fig. 3 is a modification of the arrangement shown in Fig. l, Fig. 4represents still another modification of our invention, Fig. 5 is across-sectional view taken on line 5-5 of Fig. 4, Fig. 6 is a viewsimilar to Fig. representing a modification of the arrangement of Fig.4, Fig. 'I is a cross-sectional view of another modification of ourinvention, while Fig. 8 is another view of the arrangement of Fig. '7.

Referring now'to Fig. 1, we have provided' in an electric circuitinterrupter of the gas-blast type an arc-extinguishing structurecomprising a chamber defined by a cylinder or casing of insulatingmaterial 10, which is closed at one end by I6 cooperating with fixedelectrode or contact I2.

' Although we have illustrated electrodes l2 and I6 as of thebutt-contact type, it will be understood by those skilled in the artthat any suitable type of contacts may be used.

Insulating cylinder ID houses in fixed relationship therewith a secondstationary contact member Il which is disposed towards the end ofcylinder lremote from the enclosing cap Ii. Fixed contact I1 may be ofany suitable type and is illustrated as comprising a plurality ofmembers held together by means of a garter spring I8 so as to form asleeve-type contact.- A suitable connection I9 leads from stationaryContact I1 to the exterior of the cylinder I0 so that connection withvthe external electric circuit, not shown, may be made. Rod contact I5 isprovided with a movable contact in the form of a collar 2|] which may beformed integrally therewith, as shown, and is adapted to engage withstationary contact II in the closed position of the circuit breaker. Inorder to provide for series breaks in the electric circuit through thecircuit breaker, the moV- v able rod contact I5 is provided-with asleeve 2l of insulating material, such as horn fiber, which evolves anarc-extinguishing gas when subjectedl means of a metal cap II threadedthereto von are provided cylindrical masses of insulating material 22,23, 2t, and 25 disposed within insulating cylinder lll so that shroudedrod contact i5 moves through a closely tting axial bore 2l provided inthis mass of insulating material. Insulating material 23, 24, and 25 arepreferably composed of a gas-evolving substance, such as horn fiber orthe like, so as to produce an arcextinguishing gas when subjected to theheat or contact of an arc. A suitable passage 28, substantially parallelto the axis of cylinder it, is ,provided in the mass of insulatingmaterial 22 so as to interconect the pressure-generating space adjacentcollar 20 with the space adjacent electrodes l2 and i6, all withininsulating cylinder lll. Arc-extinguishing gas produced in the chamberadjacent collar 20 is forced through passage 28 where it is cooled bythe walls of the passage and thereafter enters the space within cylinderI adjacent xed contact l2.

The wall of cylinder it adjacent contact i2 is between the pairs ofseparable contacts, there so that the arc-extinguishing gas from passage28 may be deflected by end cap li and driven lacross the'arc drawnbetween electrodes i2 and I 6. To aid in extinguishing this arc, we haveprovided a plurality oi bailies 3@ closely adjacent the path of movementof rod contact i5 and perpendicularly arranged with respect to suchpath, these baliles being disposed at progressively greater .axialdistances from xed contact l2. Preferably, these baiiles have theportions thereof adjacent the path of movement of rod contact` l5 formedof a conducting material or metal 39a and are provided withcontinuations of insulating material 36h so as to tend to segregate thearc into a plurality of portions when driven into this baie structure.The conducting portions 39a of b aiiles 3U are preferably connected withdifferent tapping points of a resistance tl, one yend of vwhich isconnected with the end cap ii and the purpose of Which will be set forthin greater detail hereinafter.

.As a further aid indnterrupting the circuit, the wallof cylinder i@ andthe masses of insulating material 22, 23 are constructed to provide aradial passage 32 to the exterior of cylinder or casing l past whichelectrode it isA eventually ,moved and through which a cross blast ofgas mayilow for causing the iinal interruption of the circuit.

'In the operationvof the above-described arrangement upon axial movementof rod contact i5 to cause separation of the electrodes, collar 2@willilrst be disengaged from stationary contact ll whereby an arc willbe drawn and pressure set up in the space enclosing said collar andassociated contact. Furthermore, the action of the heat of the arc ongas-evolving material 2d will cause the generation ofA large amounts ofarcfini ratedto drawa second arc and this gas will be 'deflected so asto now across this .second are forcing it into the bailley structurecomprising bailles 30. `.ils electrode iii moves past the conductingportion 30a of therst baille at, the arc will be urged against saidconducting -bar by the cross gasblast so that a portion of resistance 3l.will be placed in .parallel with the varc and eventually the arccurrent will be transferred to such portion of the resistance and the`arc between electrode l2 and conducting portion 30a of the iirst baille30 will be extinguished. Similarly, as the end of electrode'l moves pastthe 00naaeaeee l xlv. when electrode i6 moves past the conductingportion of the last baille 30, which position isI -shown in Fig. l, thearc will be connected ln serleswith all of resistance 3i. It will beseen that, `-`with this arrangement, resistance is inserted in serieswith the arc and the value of this resistance progressively increasedwhereby the current which is finally interrupted is very much reduced.When electrode le moves past radial passage S2, the blast of gas throughthis passage across the are will cause iinal interruption of thecircuit.

By arranging the masses of insulating material 22 and 23 so as toclosely conne shrouded rod contact l. substantially all of the gasproduced adjacent collar 2@ is caused to ow across the arc and isavailable for extinction of the latter.A

Gas-evolving insulating materialz is also preferably arranged to closelyconfine collar 2u so as to increase the arc-extinguishing gas produced.

In Fig. 2, we have shown a'modiication of the circuit breaker of Fig. 1in which material of the arc-quenching gas-producing type and a shroudedrod contactare employed but which is not arranged for insertingresistance in the circuit to be interrupted. This circuit breaker alsocomprises an insulating casing or cylinder till, which denes a chamber33. One end of this chamber is closed by means of an end cap 35 providedwith a central opening 3d and which houses a resilient socket contact 8lextending axially into chamber 33. This socket contact or electrode 3lcooperates with an electrode 3d mcuntedon the end of rod contact 39which is arranged for reciprocation within cylinder 3Q iby a suitableoperating mechanism, not shown. As in Fig. 1, rod contact 89 isprovided, with an'insulating sleeve or shroud it preferably ofgas-producing material and a collar il which cooperates with a suitablestationary contact l2 mounted in cylinder Si remote from metal end cap35 and in axial alignment with iixed contact 3l. Fixed contacts @l andd2 are suitably connected to an external circuit et. The arrangement ofcontacts 8l, 38, di, i2 is preferably such that collar di will bevdisengaged from the stationary contact d2 tov draw an arc before theelectrode 38 mounted on the end of rod contact 3S uncovers the openingor discharge port 36 in cap 35 whereby pressure will be set up withinchamber t3 by the action of. the arc, which pressure is suddenlyrelieved upon separation of contacts 3l and 38 and a sudden discharge ofthe gas produced in the chamber 33 is obtained adjacent the second arcdrawn.

Cylinder 36 is preferably provided with a' plurality of axially spacedannular disks M of opening through which rod contact 3s is adapted tomove and are provided with perfcrations gas flowing in this manner willbe obtained as rod through which'the gas produced by the arc drawnbetween collarlli and fixed contact t2 is adaptedcto iow axially of thecylinder 3d. In

this arrangement, the gas produced will flow radially on to the arc allaround the latter and a progressively greater number oi streams of thecontact 39 recedes from the end cap 35 past the several disks 44 insuccession.

Instead of being of circular form as illustrated, it will be understoodby those skilled in the art that rod contact 39 may be of rectangularsection disposed so that the gas iiows in the direction of the widerdimension of said rod, that is to say, so that the width of the gas pathcorresponds to the narrower vdimension of the rod contact, whereby thedischarge outlet 36 may, because it is narrow, be comparatively smalland the available arc-quenching gases more efficiently utilized for theextinction of the arc.

'Ihe operation of the circuit breaker of Fig. 2 will be understood fromthe description set forth in connection with Fig. 1.

In Fig. 3, we have disclosed a modification of the circuit breaker ofFig. 1 wherein the operation of the contacts is inverted. Accordingly,as in Fig. 1, we have illustrated an insulating casing 41 having one endthereof closed by a cap 48 suitably supporting a fixed contact 49extending axially into the chamber defined by casing 41. As in Fig. 1, ashrouded rod contact 50 provided with an insulating sleeve ofgas-evolving material i is arranged for axial movement within casing 41and one end thereof is provided with an lelectrode 52 'for cooperatingwith fixed contact 49. Rod contact 50 is also provided with a collar 53which is arranged to cooperate with a suitable stationary contact 54.Contacts 49 and 54 are suitably connected -to 'the external electriccircuit, `not shown. Electrode 52 and collar 53 are so arranged onrodcontact 50 as contrasted with the corresponding parts of Fig. 1 thatan arc is drawn first between electrodes or contacts 49 and 52 so as toproduce a gas pressure which is used to extinguish the arc later drawnbetween collar 53 and stationary contact 54. Preferably, rod contact 50is provided with a central axial bore 55 terlal which is mounted toreciprocate with rod contact 50. Said cylindrical block 5I is provided iwith one or more longitudinal vpassages 32 by which the arc gases areled along the rod to an opening 5B in the side of collar 53 where theyare deflected to form a cross blast as is described hereinafter.Insulating cylinder or casing 41 is providedwith an opening 51 in theform oi an arc chute adjacent stationary contact 54 on the side thereofremote Afrom end cap 43. Suitable baliies 58 similar to baiiles 39 ofFig. 1 are disposed across discharge opening or arc chute 51 in the wallof cylinder 41. As in Fig. 1, these bafiles are preferably provided withconducting portions 58a adjacent collar 53 and insulating portions 58hremote from collar 53. To aid in interrupting the arc, a resistance, notshown, similar to resistance 3l of Fig. l is preferably connected -tofixed contact 54 and tapping points thereof are connected to theconducting portions 58a of baiiles 53. V

By means of the axial bore or passage in rod contact 50, an increasedtendency to arc extinction is obtained since the gases formed betweenelectrodes 49 and 52 will be cooled and any metallic vapor produced bythe arc will be condensed in flowing-through this passage. Preferablyelectrodes 49 and 52 are closely shrouded by sleeves of gas-producingmaterial 59 and 60. It will be seen, furthermore, that with thisarrangement, the gases produced adjacent the electrodes 49 and 52 arecompelled to flow through passage 55 thereby driving the arc drawnbetween collar 53 and fixed contact 54 into the arc chute 51 and bafflestructure comprising bafiles 58.

It may also be desirable to provide a flow of gas external of rodcontact 50 and, accordingly, we have provided a cylinder 6l ofinsulating mathrough which the gases produced adjacent contact 49 passto the discharge outlet or arc chute 51v in casing 41. These passages i2also serve to cool the gases produced and to condense any metallic vaporincident to the drawing of the arc between elec-trodes 49 and` 52. As inFig. 1, .insulating material 5|, 59, 69, and 6| is preferably formed offiber or other gas-evolving material so as to produce large quantitiesof arc-quenching gas.

The operation of the cross-blast air circuit breaker of Fig. 3 will beobvious to those skilled in the art in view of the detailed descriptionset forth in connection with Fig. l.

In Figs. 1 to 3, we have disclosed air-blast circuit breakers of thetype wherein two arcs in series are drawn, one to generate a gaspressure which will extinguish the other arc drawn. It will beunderstood by those skilled in the art that it is not essential incarrying out this invention that the arc over which the gases producedare caused to flow should be separate from the arc producing thesegases. Thus, the arrangement may b'e such that separation of a pair ofcontacts results initially in drawing an arc by which gas pressure isobtained while further movement of the contacts opens passages by whichthe pressure is released and a flow of gas obtained across the arc forextinguishing purposes. Such an arrangement is shown in Figs. 4 and 5wherein a fixed socket contact 64 is mounted within a chamber orenclosure 53 defined by suitable cupshaped structure having a threadedextension 66 adapted to be connected to an external electrical circuit,not shown. Cup-shaped member 65 is closed by means of a block ofinsulating material $1 constructed with a passage extendingperpendicularly to the axis of member 55 and ending in an arc chute 68.This arc chute communicates with chamber 63 by means of a passageA 69.Asuitable rod contact 1l is arranged for reciprocal movement Within theenclosure 53 and is adapted to cooperate with stationary or fixedcontact 64. The end of rod contact 10 cooperating with contact 64 ismade hollow in order to accommodate a suitable filler pencil 12preferably made of a hard fiber or suitable articial resin for producingarc-extinguishing gas when subjected to the action of the arc. Rodcontact 10 moves through an opening 1| in the wall of insulating block61 remote from fixed con tact 64.

Secured to insulating block 61 within the 'enclosure 63 is a cylindricalbody 13 of gas-produc-v ing material of any suitable type such as fiberor the like which is provided with a central perforation through whichrod contact 10 is adapted to move while being engaged or disengaged fromstationary contact 64. Cylindrical body 13 and socket contact 64practically fill the enclosure $3 defined by cup-shaped structure 65 andinsu1at.

ing block 61. A plurality of radialpassages 14 are provided incylindrical. body 13 extending from the center to the peripherythereof,v the purpose of which will be hereinafter described.

Rod contact 10 moves with only a very small clearance through the boreci the gas-producing material 13 and the passage 69 leading to arc chute68 so that the inner surfaces of said passages areclosely adjacent thesides of the Contact rod, as best shown in Fig. 5. It will be seenthat,with this arrangement upon retraccontact 64, an arc will be drawn whichwill act upon the gas-producing material making up the,

iiller pencil l2 and the cylindrical body 13, thereby producingconsiderable quantities of arc-quenching gas. This gas will vbe retainedwithin the enclosure 63 until the end of the rod contactlll moves intothe passage 89 leading to arc chute 68 when the flow of gas in passage69 is deflected so as to be directed across the arc into arc chute 68 toextinguish the same. Suitable baiiies 'l5 which comprise a metal portion15a adjacent contact rod 18 and an insulating portion ll5b remote fromrod contact 'l are provided. As in Fig. 1, the conducting portions a vquired contact pressure is obtained by virtue of u of bailles 'l5 may beassociated with different tapvping points of a resistance, not shown,the end of which would be electrically connected to stationary contact64. It will be seen from Figs. 4 and 5 that we have provided anarrangement wherein the arc-extinguishing gas or uid generated aroundcontact 84 is prevented from passing across said arc until there hasbeen a predetermined separation of the contacts whereby interruption ofthe arc may take place without danger of restriking.

Although in Figs. 4 and 5, rod contact 18 has been indicated as ofcircular cross section, it could just aswell be of rectangular crosssection. In Fig'. 6, we]` have shown a rod contact '6 of rectangularcross section associated with a cir` cuit breaker otherwise identicalwith that shown 85, suitably raised.y contact surfacesl may be providedon each of the fingers 85 adjacent deprising a at strip of conductingmaterial which is arranged to move through the aperture 88 in theenclosure 1l. In the closed circuit position,

rod contact 88 is adapted to be moved between the two sets of contactlingers 85 and the recompression springs 86.

A pair of movable ilat plates 88, ,which are formed of a suitablegas-producing material, is mounted within the enclosure Tl and extendentirely across the space therein. These plates able stors 943 areprovided to limit the movement' of these plates toward one another. Theupper` end of vrod contact 88 is rounded and the cooperating edges ofgas-producing plates 89 are chamfered so that, when the'moving contactis moved upwardly, the gas-producing plates 88 will be forced apart sothatz rod contact 88 may engage with the iixed contact comprisingfingers The free space between side plates 'i8 may be filled withadditional plates 98 of gas-producing material.- As in Fig. 4, a'plurality of baiiies 95 are provided in arc chute 8l which preferablyhave the portions thereof adjacent rod contact 88 formed of a metalconnected to suitv able tapping points on a resistance 96 having one theevolution of a gas from insulating members.

is depended upon to produce an arc-quenching gas, it has often beenfound that arcs of low- Acurrent value are incapable of levolving asulli` cient amount of gas whereas, if thespace within which the gas isproduced is decreased, arcs of high-current values develop suchdestructive pressures that the confining structure will be damaged.Accordingly, in Figs. 7 and 8, we have disclosed a cross-blast circuitbreaker having a single break similar to the'one shown in Fig. 4 whichovercomes the diiliculty just mentioned.

' A suitable arc-coniining chamber 'll is provided which is dened bymeans of a pair of side plates f 18 which are disposed parallel with andclosely adjacent to one another, being secured together by blocks orplates of insulating material 18. Fig. 8 is a side view of the circuitbreaker of Fig. '1 with one of the plates 'l8 removed. Chamber` 'Il isprovided with a rectangular aperture 80 at one end and an opening andarc chute 8| disposed substantially midway along one side of thestructure.v rl'fheend of chamber 'll-remote from aperture 80 is closedby means oi a ixed contact assembly 82 comprising an extension 83adapted to be connected to an external electrical circuit, not shown anda central depending tongue 84 extending into chamber 1l. -A plurality ofcontact ilngers 85 are suitably mounted on each side of this dependingtongue 84 and "biased toward one another by spring means 88.

In order toassure good electrical contact between-depending tongue 84and contactin'gers` end thereof connected to the fixed` contact assembly82.

plates so that it will have an increased eiect in 4evolving thearc-quenching gas from plates 89. Since the plates 89 extend into thearc chute 8l, the gas stream resulting from the abovedescribed operationis discharged as a blast forcing the Aarc into the baffle structure in amannerl described in connection with Fig. 1. As will be understood bythose skilled in the art, should any excess gas pressure arise withinthe structure due to breaking circuit on heavy current, such excesspressure will result in the gas-producing plates 89 being forced awayfrom one another against the biasing springs 93 to relieve the pressure.v

As will be understood by those s killed in the arc-quenching gas may beof any suitable kind, for example, resins, vulcanite, ber, ebonite,halogenated diphenyl ketones or dibenzyls, methyl methacrylat'e, andother available materials.

While we have described certain particular embodiments of :ourinvention, it will be obvious to those skilled in the art that variouschanges and `modifications may be made without departing from ourinvention and w e, therefore, aim in the appended claims to cover allsuch changes and modifications as fall within the true spirit and scopeof our invention:

What we claim as new and desire to secure by Letters Patent of theUnited States is:

l. In a circuit-interrupting device comprising an arc chamber includinga plurality ofspaced annular fixed electrodes mounted therein in axialalignment, an elongated rod contact of 'conducting material havingspaced contact portions separated by a sleeve of insulating materialarranged for axial movement in said chamber, said contact portions beingspaced to engage said iixed electrodes in the closed circuit positionand separable therefrom so as to draw arcs between said contacts andelectrodes, means formed of gasevolving insulating material forgenerating a gas and developing a pressure in said chamber under theiniiuence of one of said arcs defining a passageway in said chamber forleading said gas in a direction substantially parallel with the axis ofsaid chamber, and deecting means for causing a blast of said gas to flowacross said other arc to extinguish the same.

2. In a circuit-interrupting device comprising Y a casing having an arcchute associated therewith, a pressure chamber in said casingcommunicating with said arc chute, means including an elongated rodContact having a pair of contact portions thereon separated by a sleeveof insulating material for drawing a plurality of arcs in said casing,one adjacent said arc chute and another in said pressure chamber, meansformed of gas-evolving insulating material for generating a gas anddeveloping a pressure under the influence of one of said arcs deiining apassageway in said chamber for leading said gas in the direction of saidarc chute across the arc adjacent thereto, a barile structure in saidarc chute comprising a plurality of spaced plates disposed close to andedgewise with respect to the arc adjacent said are chute, the portion ofsaid plates near said arc being formed of a conducting material, and aresistance including a plurality of tapping points, each connected toone of said conducting portions of said plates and so constructed andarranged that portions thereof are'progressively connected in serieswith said arcs during the circuit-interrupting operation of said device.

3. In a circuit-interrupting device comprising an arc chamber having anarc chute associated therewith and including a plurality of iixedelectrodes mounted therein in axial alignment, an elongated rod contactof conducting material having spaced contact portions separated by asleeve of insulating material arranged for axial movement in saidchamber, said contact portions being spaced to engage said xedelectrodes in the closed circuit position and separable therefrom sc asto draw arcs between said contacts and electrodes, means formed of agas-evolving insulating material for generating a gas and developing apressure in said chamber under the influence of one of said arcsdefining a passageway in said chamber for leading said gas in adirection substantially parallel with the axis of said chamber towardsaid arc chute, and defiecting means for causing a blast of said gas toiiow across said other arc into said arc chute to extinguish the same.

4. An electric circuit breakercomprising an arc-confining chamber, aplurality of spaced fixed contacts mounted in axial alignment in saidchamber, an elongated movable rod contact of. conducting material havingspaced contact portions separated by a sleeve of gas-emitting insulatingmaterial, said contact portions being spaced to engage said fixedcontacts in the closed circuit position of said breaker and separabletherefrom by movement of said rod contact in an axial direction withrespect to said fixed contacts, means for generating anarc-extinguishing iiuid adjacent one of said xed contacts under theinfluence of the arc associated with Vrable therefrom so as to saidlast-mentioned contact, means formed of gas-evolving insulating materialdefining a passageway in said chamber for leading said gas in adirection substantially parallel with the axis of said chamber towardanother of said fixed contacts. and deflecting means for causing a blastof said gas to flow across the arc associated with said last-mentionedxed contact to extinguish the same.

5. In a circuit-interrupting device comprising an arc chamber includinga plurality of.spac ed annular xed electrodes mounted therein in axialalignment, an elongated rod contact oi conducting material having spacedcontact portions separated by a sleeve of insulating material arrangedfor axial movement'in said chamber, said contact portions being spacedto engage said xed electrodes in the closed circuit positionand'sepadraw arcs between said contacts and electrodes, means forgenerating a gas and developing a pressure in saidv chamber under theiniiuence of one of said arcs, means formed of a gas-evolving materialfor dening a passageway in said chamber for leading said gas in adirection substantially parallel with the axis of said chamber, andmeans for causing said gas to iiow radially on to said other arc in aprogressively greater number of streams as said rod contact moves withrespect to said xed electrodes.v

6. An electric circuit breaker comprising an arc-conning chamber, aplurality of spaced iixed contacts mounted in axial alignment in saidchamber, an elongated movable rod contact of conducting material havingspaced contact portions separatedby a sleeve of gas-emitting insulatingmaterial, said contact portions being spaced to engage said xed contactsin the closedcircuit position of said breaker and separable .therefromby movement of said rod contact in an axial direction with respect tosaid xed contacts, means for generating an arc-extinguishing fluidadjacent one of said xed contacts under the influence of the arcassociated with said lastmentioned contact, a passageway in said chamberfor leading said gas in a direction substantially parallel with the axisof said chamber toward a second fixed contact, and .means for causingsaid gas to ilow radially on to said arc associated with said secondxed-contact in a progressively greater number of streams as said arcassociated with said second fixed contact is increased in length.

.SYDNEY FARRER. GEORGE PAmrN.

6 "RTI'FICATE oFv ooREcTor.

Patent No. 2,267,599. December 25, 19in. A

- SYDNEY FARRER, ET AL.

It is hereby certified that error appears in the-printed specification:of the above numbered patent requiring correction as follows: Page 2,first column, line 2l, strike out "between the pairs of separablecontacts, there'r and insert ."instead --provided witha suitabledischarge opening 29"; page 5, second column, line 57, cla-11115',before "material" insert --insu1ating; and that the said Letters Patentshould be read with this correction .there- 1x1-'that the samemayconform to the record of the case in the Patent Office.'

signed mi sealed this 5rd de; of naz-ch, A. D. 191m.

Henry Van Arsdale, (Seal) Acting Commissioner of Patente.

6 .RT'I'ICATE 0F ooR'E'ori.

Pax-.mt No. 2,267,599. December 25, 19m. l,

- SYDNEY FAHBER, ET AL.

It is hereby certified that error appears in the-printed specification:of the above numbered patent requiring correction as follows: Page 2,first column, line 21, strike out between the pairs of separablecontacts there'r and insert "instead --provided witha suitable dischargeopening 29"; page 5, seoo'nd colmnn, line 57, claims', before "material"insert insu1ating; and that the said Letters 4Patent should be read withthis correction therein'umt the as me'may confer-m to the record of thecase 1n the Patent office.-

sigmd'dm sealed this 5rd any of naz-ch, A. D. 19b,2.

4 Henry Van Arsdale, (Seal) A Acting Commissioner of Patents.

